USDA-Natural Resources Conservation Service, 101 SW Main Street, Suite 1300, Portland, OR 97204-3221

99 -- SNOW PILLOW REPLACEMENT SOL NRCS-01-WCC-96. Due 052596. Contact Point, Don Huffman, (503) 414-3032, Contracting Officer, Rene' Walls, (503) 414-3212. The Natural Resources Conservation Service is seeking a source for a new sensor to be compatible with current remote data site locations and the existing SNOTEL platform. Since 1964, the NRCS Snow Survey Program has measured the snow water equivalent (SWE) using either butyl rubber or hypalon bladders, or metal tanks to weight the snowpack. Each pillow is filled with an antifreeze solution consisting of a 50/50 mix of methanol and water. Transducers convert hydraulic pressure to a voltage that is sensed and stored for later retrieval. Snow pillows are used at approximately 650 remote data sites in the NRCS snowpack telemetry system called SNOTEL. They are also used in remote applications in California, Alaska, Alberta, British Columbia, and various other foreign countries. Recently, vandalism and damage caused by wild animals has increased substantially. This has led to a heightened public awareness and an increased concern about the potential for environmental damage caused by leaking antifreeze solution. NRCS is concerned as well. The Water and Climate Center is committed to eliminating the hazzard by replacing existing pillows with a next-generation fluidless sensor. The following are minimum requirements necessary for a new sensor to be compatible with current remote data site locations and the existing SNOTEL telemetry platform. 1. Physical a. Maximum dimensions cannot exceed 8' x 10' in surface area. b. Maximum weight cannot exceed 100 pounds. c. Device must be transportable via helicopter, pack-horse, or all-terrain vehicle. 2. Environmental a. Device cannot contain fluids or materials designated as being hazardous to the environment. b. Installation must be able to be completed by no more than two people with a minimum of ground leveling or other site disturbance. c. Sensor must withstand the forces of snow creep when installed on slopes. d. Sensor must negate any effects caused by ice lensing, snow bridging, or other deformation within the snowpack. e. Sensor must remain operational through a temperature range of from -50 degrees celsius to +50 degrees celsius. 3. Electronic a. All electronic components must be waterproof or have waterproof housing. b. Excitation voltage will be nominal 5.0, 7.5, or 10.0 vdc with no more than a 10 ma current draw. c. Sensor output will be analog, 0.0 to 5.0 vdc, stabilizing in less than 80 milliseconds. d. Resolution will be 0.01 inches SWE or better. e. Output values must remain stable under non-changing snow conditions. f. Long-term drift cannot exceed 0.1 percent per year. 4. Other Per unit purchase price must be comparable to that of the existing pillow installation, including anti-freeze, pressure transducer, and associated plumbing hardware. (117)

Loren Data Corp. http://www.ld.com (SYN# 0291 19960429\99-0002.SOL)